1 files changed, 242 insertions, 0 deletions
diff --git a/tests/loader/variants.py b/tests/loader/variants.py
new file mode 100644
index 000000000..bdea0642f
--- /dev/null
+++ b/tests/loader/variants.py
@@ -0,0 +1,242 @@
+import os
+import pytest
+
+from buildstream import LoadError, LoadErrorReason
+from buildstream._loader import Loader
+from buildstream._metaelement import MetaElement
+
+DATA_DIR = os.path.join(
+    os.path.dirname(os.path.realpath(__file__)),
+    'variants',
+)
+
+##############################################################
+#                 Test Basic Failure Modes                   #
+##############################################################
+@pytest.mark.datafiles(DATA_DIR)
+def test_variant_not_list(datafiles):
+
+    basedir = os.path.join(datafiles.dirname, datafiles.basename)
+    loader = Loader(basedir, 'elements/variants-not-list.bst', None, None)
+
+    with pytest.raises(LoadError) as exc:
+        element = loader.load()
+
+    assert (exc.value.reason == LoadErrorReason.INVALID_DATA)
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_variant_unnamed(datafiles):
+
+    basedir = os.path.join(datafiles.dirname, datafiles.basename)
+    loader = Loader(basedir, 'elements/unnamed-variant.bst', None, None)
+
+    with pytest.raises(LoadError) as exc:
+        element = loader.load()
+
+    assert (exc.value.reason == LoadErrorReason.INVALID_DATA)
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_variant_bad_name(datafiles):
+
+    basedir = os.path.join(datafiles.dirname, datafiles.basename)
+    loader = Loader(basedir, 'elements/variant-bad-name.bst', None, None)
+
+    with pytest.raises(LoadError) as exc:
+        element = loader.load()
+
+    assert (exc.value.reason == LoadErrorReason.INVALID_DATA)
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_variant_only_one(datafiles):
+
+    basedir = os.path.join(datafiles.dirname, datafiles.basename)
+    loader = Loader(basedir, 'elements/only-one-variant.bst', None, None)
+
+    with pytest.raises(LoadError) as exc:
+        element = loader.load()
+
+    assert (exc.value.reason == LoadErrorReason.INVALID_DATA)
+
+##############################################################
+#                Test Simple Variant Compositing             #
+##############################################################
+@pytest.mark.datafiles(DATA_DIR)
+def test_variant_simple_composite_default(datafiles):
+
+    basedir = os.path.join(datafiles.dirname, datafiles.basename)
+    loader = Loader(basedir, 'elements/simple-variant-compositing.bst', None, None)
+
+    element = loader.load()
+
+    assert(isinstance(element, MetaElement))
+    assert(element.kind == 'pony')
+
+    # Without specifying a variant, the default (first) should have been chosen
+    assert(element.config.get('somedata') == 5)
+    assert(element.config.get('pony-color') == 'pink')
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_variant_simple_composite_pink_pony(datafiles):
+
+    basedir = os.path.join(datafiles.dirname, datafiles.basename)
+    loader = Loader(basedir, 'elements/simple-variant-compositing.bst', 'pink', None)
+
+    element = loader.load()
+
+    assert(isinstance(element, MetaElement))
+    assert(element.kind == 'pony')
+
+    # We explicitly asked for the pink variation of this pony
+    assert(element.config.get('somedata') == 5)
+    assert(element.config.get('pony-color') == 'pink')
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_variant_simple_composite_blue_pony(datafiles):
+
+    basedir = os.path.join(datafiles.dirname, datafiles.basename)
+    loader = Loader(basedir, 'elements/simple-variant-compositing.bst', 'blue', None)
+
+    element = loader.load()
+
+    assert(isinstance(element, MetaElement))
+    assert(element.kind == 'pony')
+
+    # We explicitly asked for the blue variation of this pony,
+    # which has the side effect of overriding the value of 'somedata'
+    assert(element.config.get('somedata') == 6)
+    assert(element.config.get('pony-color') == 'blue')
+
+##############################################################
+#               Test Variant Dependency Plotting             #
+##############################################################
+
+# Convenience for asserting dependencies
+#
+def assert_dependency(element, index, name, key, value):
+
+    # Test that the dependency we got is the pink color by default
+    assert(len(element.dependencies) >= index + 1)
+    dep = element.dependencies[index]
+
+    assert(isinstance(dep, MetaElement))
+    assert(dep.name == name)
+    assert(isinstance(dep.config, dict))
+    assert(dep.config.get(key) == value)
+
+    return dep
+
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_variant_simple_dependency_default(datafiles):
+
+    basedir = os.path.join(datafiles.dirname, datafiles.basename)
+    loader = Loader(basedir, 'elements/simple-dependency-variants.bst', None, None)
+    element = loader.load()
+
+    assert(isinstance(element, MetaElement))
+    assert(element.kind == 'pony')
+
+    # Test that the default is a pink pony
+    assert_dependency(element, 0, 'simply-pink', 'color', 'pink')
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_variant_simple_dependency_pink_pony(datafiles):
+
+    basedir = os.path.join(datafiles.dirname, datafiles.basename)
+    loader = Loader(basedir, 'elements/simple-dependency-variants.bst', 'pink', None)
+    element = loader.load()
+
+    assert(isinstance(element, MetaElement))
+    assert(element.kind == 'pony')
+
+    # Test that the explicit pink dependency is correct
+    assert_dependency(element, 0, 'simply-pink', 'color', 'pink')
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_variant_simple_dependency_blue_pony(datafiles):
+
+    basedir = os.path.join(datafiles.dirname, datafiles.basename)
+    loader = Loader(basedir, 'elements/simple-dependency-variants.bst', 'blue', None)
+    element = loader.load()
+
+    assert(isinstance(element, MetaElement))
+    assert(element.kind == 'pony')
+
+    # Test that the explicit blue dependency is correct
+    assert_dependency(element, 0, 'simply-blue', 'color', 'blue')
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_variant_indirect_dependency_default(datafiles):
+
+    basedir = os.path.join(datafiles.dirname, datafiles.basename)
+    loader = Loader(basedir, 'elements/indirect-dependency-variants.bst', None, None)
+    element = loader.load()
+
+    assert(isinstance(element, MetaElement))
+    assert(element.kind == 'pony')
+
+    # Test that the default is a blue pony-color by default
+    simple = assert_dependency(element, 0, 'simple-dependency-variants', 'pony-color', 'blue')
+
+    # Test that the element we depend on now depends on the blue color
+    assert_dependency(simple, 0, 'simply-blue', 'color', 'blue')
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_variant_indirect_dependency_blue_pony(datafiles):
+
+    basedir = os.path.join(datafiles.dirname, datafiles.basename)
+    loader = Loader(basedir, 'elements/indirect-dependency-variants.bst', 'blue', None)
+    element = loader.load()
+
+    assert(isinstance(element, MetaElement))
+    assert(element.kind == 'pony')
+
+    # Test for a blue pony-color
+    simple = assert_dependency(element, 0, 'simple-dependency-variants', 'pony-color', 'blue')
+
+    # Test that the element we depend on now depends on the blue color
+    assert_dependency(simple, 0, 'simply-blue', 'color', 'blue')
+
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_variant_indirect_dependency_pink_pony(datafiles):
+
+    basedir = os.path.join(datafiles.dirname, datafiles.basename)
+    loader = Loader(basedir, 'elements/indirect-dependency-variants.bst', 'pink', None)
+    element = loader.load()
+
+    assert(isinstance(element, MetaElement))
+    assert(element.kind == 'pony')
+
+    # Test for a blue pony-color
+    simple = assert_dependency(element, 0, 'simple-dependency-variants', 'pony-color', 'pink')
+
+    # Test that the element we depend on now depends on the blue color
+    assert_dependency(simple, 0, 'simply-pink', 'color', 'pink')
+
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_engine_resolve_agreement(datafiles):
+
+    basedir = os.path.join(datafiles.dirname, datafiles.basename)
+    loader = Loader(basedir, 'elements/tricky.bst', None, None)
+    element = loader.load()
+
+    assert(isinstance(element, MetaElement))
+    assert(element.kind == 'tricky')
+
+    # Test the first dependency
+    first = assert_dependency(element, 0, 'tricky-first', 'choice', 'second')
+    second = assert_dependency(element, 1, 'tricky-second', 'choice', 'second')
+
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_engine_disagreement(datafiles):
+
+    basedir = os.path.join(datafiles.dirname, datafiles.basename)
+    loader = Loader(basedir, 'elements/disagreement.bst', None, None)
+
+    with pytest.raises(LoadError) as exc:
+        element = loader.load()
+
+    assert (exc.value.reason == LoadErrorReason.VARIANT_DISAGREEMENT)